Jerusalem (CNSNews.com) - Palestinians called for revenge and launched several rocket and mortar attacks on Israeli communities on Tuesday, after an Israeli helicopter strike in the Gaza Strip. The military said the target was a camp used to train terrorists.

At least 13 Palestinians were killed in the overnight raid on the Shajaiyeh section of Gaza City, known as a Hamas stronghold.

Dozens of wounded Palestinians were taken to Gaza's main hospital, where hundreds more Palestinians gathered outside, calling for revenge.

The Israeli strike on a field named after Hamas founder Sheikh Ahmed Yassin was the largest since May, when some 30 Palestinians and 13 Israelis soldiers were killed in a week of fighting.

The Hamas' military wing said that the Israeli operation had hit a youth camp where a group of fighters was training. But Israeli army Chief of Staff Moshe Ya'alon said the Israeli Air Force had attacked a terrorist training camp, not a youth camp.

An unnamed senior Hamas terrorist, involved in carrying out deadly terror attacks, led the training at the site, the army said.

The site was used to train terrorists how to plant and activate explosive devices, how to launch RPG's and Kassam rockets, how to infiltrate into Israeli communities and military posts and how to seize control of a car in order to kidnap Israeli civilians and soldiers, the army said in a statement.

Two weeks ago, a powerful blast at the field killed a well-known Hamas militant and wounded several others due to what the army described as a "technical difficulty" with an explosive device intended for an Israeli target.

The army indicated that an attempt to smuggle a suicide bomb belt from the Gaza Strip into Israel a week ago was also connected to the training field.

Calling it an "ugly Israeli crime" Hamas spokesman Mushir al-Masri was quoted in news agency reports saying the incident would not go "unpunished."

Islamic Jihad said Israel would "pay for its crimes with a heavy price of blood and bodies of Zionists [Israelis] in the streets of al-Quds [Jerusalem], Beit Lid, Dizengoff [Tel Aviv street] and Hadera," referencing places where deadly terror attacks have occurred in the past.

One Israeli was lightly wounded in one of two Kassam rocket attacks on Israeli communities inside Israel on Tuesday. Three mortar shells also slammed into the Gush Katif area of the Gaza Strip.

The operation came just one week after Hamas claimed responsibility for twin suicide bombings in which 16 Israelis were killed.

Israel accused the Hamas leadership in Damascus of orchestrating that attack in the southern Israeli city of Beersheva and warned that it would seek out terrorists wherever they were.

According to the Jerusalem Post, the London-based paper Asharq Al-Awsat quoted an unnamed Arab diplomatic sources in the Jordanian capital saying that Hamas officials had fled Damascus, fearing Israeli reprisals, and had taken refuge in Lebanon and Qatar.